Uh oh! Wolfram|Alpha doesn't run without JavaScript.
Please enable JavaScript. If you don't know how, you can find instructions
here
.
Once you've done that, refresh this page to start using Wolfram|Alpha.
sqrt(4 pi (4237km)^2 * gravitational constant*earth density/(2pi/(seconds in a day))^2)
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random